GIS-based DRASTIC and composite DRASTIC indices for assessing groundwater vulnerability in the Baghin aquifer, Kerman, Iran

Abstract

Abstract. The present study estimates the Kerman–Baghin aquifer vulnerability using DRASTIC and composite DRASTIC (CDRASTIC) indices with the aid of geographic information system (GIS) techniques. Factors affecting the transfer of contamination, including water table depth, soil media, aquifer media, the impact of the vadose zone, topography, hydraulic conductivity, and land use, were used to calculate the DRASTIC and CDRASTIC indices. A sensitivity test was also performed to determine the sensitivity of the parameters. Results showed that the topographic layer displays a gentle slope in the aquifer. Most of the aquifer was covered with irrigated field crops and grassland with a moderate vegetation cover. In addition, the aquifer vulnerability maps indicated very similar results, identifying the north-west parts of the aquifer as areas with high to very high vulnerability. The map removal sensibility analysis (MRSA) revealed the impact of the vadose zone (in the DRASTIC index) and hydraulic conductivity (in the CDRASTIC index) as the most important parameters in vulnerability evaluation. In both indices, the single-parameter sensibility analysis (SPSA) demonstrated net recharge as the most effective factor in vulnerability estimation. According to the results, parts of the studied aquifer have a high vulnerability and require protective measures.

Elemental composition of salt and vulnerability assessment of saline groundwater sources selected based on ethnoarchaeological evidence in Romania

“…Aquifer type-The "A" parameter controls the movement of groundwater streams within the aquifer (Aller et al, 1985;Singh et al, 2015;Malakootian and Nozari, 2020). In the case of the investigated SGS, information from available hydrogeological maps (scale 1:100,000) and direct observations were used to create the aquifer media layer.…”

“…This analysis was conducted on salt samples extracted from 198 brine sites, which were selected based on ethnoarchaeological evidence. The second method adopted was the DRASTIC and DRASTIC-LU vulnerability assessment system (Aller et al, 1985;Martínez-Bastida et al, 2010;Malakootian and Nozari, 2020). Overall, the DRASTIC methodology, developed by the United States Environmental Protection Agency (US EPA), is a standardized approach for evaluating intrinsic groundwater pollution potential.…”

“…Overall, the DRASTIC methodology, developed by the United States Environmental Protection Agency (US EPA), is a standardized approach for evaluating intrinsic groundwater pollution potential. The method is based on seven key hydrogeological settings: depth to groundwater (D) (Baghapour et al, 2016), net recharge (R) (Chitsazan and Akhtari, 2009;Ghosh and Kanchan, 2016), aquifer type (A) (Aller et al, 1985;Singh et al, 2015;Malakootian and Nozari, 2020), soil type (S) (Aller et al, 1985;Singh et al, 2015), topography/slope (T) (Aller et al, 1985;Malakootian and Nozari, 2020), impact of the vadose zone (I) (Shirazi et al, 2012;Singh et al, 2015;Malakootian and Nozari, 2020) and hydraulic conductivity (C) (Aller et al, 1985;Kardan Moghaddam et al, 2017;Neshat and Pradhan, 2017;Malakootian and Nozari, 2020). In the case of DRASTIC-LU index , the DRASTIC index is modified by adding the land use (LU) parameter as a new pollution potential factor (Malakootian and Nozari, 2020).…”

“…The method is based on seven key hydrogeological settings: depth to groundwater (D) (Baghapour et al, 2016), net recharge (R) (Chitsazan and Akhtari, 2009;Ghosh and Kanchan, 2016), aquifer type (A) (Aller et al, 1985;Singh et al, 2015;Malakootian and Nozari, 2020), soil type (S) (Aller et al, 1985;Singh et al, 2015), topography/slope (T) (Aller et al, 1985;Malakootian and Nozari, 2020), impact of the vadose zone (I) (Shirazi et al, 2012;Singh et al, 2015;Malakootian and Nozari, 2020) and hydraulic conductivity (C) (Aller et al, 1985;Kardan Moghaddam et al, 2017;Neshat and Pradhan, 2017;Malakootian and Nozari, 2020). In the case of DRASTIC-LU index , the DRASTIC index is modified by adding the land use (LU) parameter as a new pollution potential factor (Malakootian and Nozari, 2020). The role of LU for SGS vulnerability assessment was determined by the fact that several sites are shallow saline waters, which indicates that the LU significantly contribute to the vulnerability of these type of sites.…”

Groundwater Vulnerability and Potentially Toxic Elements Associated with the Iron Mining District of Ouixane (Northeast of Morocco)

“…A single-parameter sensitivity measure is developed to evaluate the impact of each of the DRSTI parameters on the groundwater vulnerability index. It allows comparing the "effective" weight with their "theoretical" weight [33], as has been applied in different other studies [27,34,35]. The "effective" weight of each parameter in each subarea is calculated using Equation (3):…”